| public Decompress ( byte compressed, int compressedOffset, int compressedSize ) : byte[] | ||
| compressed | byte | |
| compressedOffset | int | |
| compressedSize | int | |
| 리턴 | byte[] | |
public override int Read(byte[] buffer, int offset, int count)
{
if (compressionMode != CompressionMode.Decompress || decompressor == null)
{
throw new InvalidOperationException("Cannot read if not set to decompression mode.");
}
int readCount = 0;
int firstByte = stream.ReadByte();
// first byte can indicate stream header, we just read it and move on.
if (firstByte == StreamIdentifier)
{
CheckStreamHeader();
}
else if (firstByte == UncompressedType)
{
var length = GetChunkUncompressedLength();
readCount = ProcessRemainingInternalBuffer(buffer, offset, count);
if (readCount != count)
{
stream.Read(internalBuffer, 0, length);
Array.Copy(internalBuffer, 0, buffer, offset, count - readCount);
internalBufferIndex = count - readCount;
internalBufferLength = length;
}
}
else if (firstByte == CompressedType)
{
var length = GetChunkUncompressedLength();
count = ProcessRemainingInternalBuffer(buffer, offset, count);
// we at most have 64kb in the buffer to read
byte[] tempBuffer = new byte[1 << (BLOCK_LOG + 1)];
stream.Read(tempBuffer, 0, tempBuffer.Length);
decompressor.Decompress(tempBuffer, 0, tempBuffer.Length, internalBuffer, 0, length);
Array.Copy(internalBuffer, 0, buffer, offset, count);
internalBufferIndex = count;
internalBufferLength = length;
}
else if (firstByte > 0x2 && firstByte < 0x7f)
{
throw new InvalidOperationException("Found unskippable chunk type that cannot be undertood.");
}
else
{
// getting the length and skipping the data.
var length = GetChunkUncompressedLength();
stream.Seek(length, SeekOrigin.Current);
readCount += length;
}
return(readCount);
}
public static byte[] Uncompress(byte[] compressed)
{
var target = new SnappyDecompressor();
return(target.Decompress(compressed, 0, compressed.Length));
}
public static byte[] Uncompress(byte[] compressed, int compressedOffset = 0, int compressedSize = -1)
{
return(decompressor.Decompress(compressed, compressedOffset, compressedSize >= 0 ? compressedSize : compressed.Length - compressedOffset));
}